overclocking ram beyond its rated specification is 50-50 me thinks. that's why the higher rated ram were sold for a much higher price because you only get like a few % out of a batch that can achieve such high quality.
I would not bother overclocking a 1600mhz ram to 2133/2400 at this point because you probably wont get much "mileage" out of them at this point of their age.
IMHO, It's better to look for a 2400 ddr3 kit. you just might get lucky somebody wanted to upgrade and sell their kits, and most of them come with lifetime manufacturer warranties. Just learn to avoid the manufacturers with "untransferable" warranty because the warranty goes to void if the original owners sell them to someone else, and you don't want to end up with an expensive kit that can't be repaired. but in all likelihood, if the sticks fail, the manufacturers probably wont have anything comparable in stock to exchange as a replacement. thus, I would not recommend overclocking those ram.
Stankenestor :
I can get a 4790k for 200$. Im wondering if maybe i should get new ddr3 2x8 gb 2133 mhz or 2400mhz and overclock the ram to make my processor run better. I dont want to run 1600 mhz ram, considering i want to play games like fallout 4 (modded as well). According to the techspot benchmark of the game, going from 1333 mhz ddr3 ram to 2400 mhz provided a massive 67% increase in minimum frame rate for the Core i7-4770K.
So if i get a used 4790k, should i perhaps buy new ddr3 ram? Or get another 8gb stick and try and overclock my 1600 mhz ram? completely new 16gb 2400 mhz ram would cost another 150$. Perhaps i can find a good deal for used high speed ddr3 ram